共查询到19条相似文献,搜索用时 187 毫秒
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为了缩短生产周期,更好地保证瓷套的胶装质量。开发了新型的S_1胶合剂(硫铝酸盐水泥胶合剂).并与S胶合剂(硅酸盐水泥胶合剂)各项技术性能进行了对比试验。结果表明,S_1水泥胶合剂具有早期强度高、后期强度发展快的特点,并有较好的流动性且不分层;S_1水泥胶合剂比S水泥胶合剂的机械强度高,1d的强度提高了81.3%,3d的机械强度提高了59.0%,28d的强度提高了50.9%。S_1水泥胶合剂还具有凝结时间较快、低收缩、低碱性、耐蚀性及抗冻性好的特点,增加了产品的整体强度,显著提高了经济效益。 相似文献
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提高水泥胶合剂强度的研究试验 总被引:1,自引:1,他引:0
为了提高水泥胶合剂的强度,对硅酸盐水泥和硫铝酸盐水泥胶合剂进行了研究试验。结果表明:采用高标号早强PⅠ型硅酸盐水泥可提高胶合剂强度;在硅酸盐水泥胶合剂中加入适量的微集料,能明显提高胶合剂强度;硫铝酸盐水泥胶合剂在强度上比硅酸盐水泥胶合剂具有显著的优势,而且硫铝酸盐水泥体积膨胀率与硅酸盐水泥胶合剂相近,不存在后期强度倒缩现象,能够用于高强度绝缘子生产。 相似文献
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采用正交试验设计法,改进普通硅酸盐水泥胶合剂的配方,使水泥胶合剂试条的强度由787kgf/cm~2上升到1202kgf/cm~2,在用于圆柱头16吨钢化玻璃绝缘子和瓷绝缘子的胶装试验时,机械破坏强度值完全达到了产品设计要求。 相似文献
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水泥胶合剂与瓷件、金属附件统称为胶装型绝缘子的3大组成。其中,水泥胶合剂起整体结构的组织连接作用,它的品质直接关系绝缘子的性能、寿命及可靠性,其强度是直接影响绝缘子强度性能的重要因素。 牡丹江水泥厂根据牡丹江电瓷总厂对高强度胶装水泥的需求,依据JB4307—86《绝缘子胶装用水泥胶合剂技术条件》进行了研制工作。 高强度水泥胶合剂一般以标号525以上的硅酸盐水泥或专门 相似文献
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本文介绍由瓷质悬式绝缘子水泥胶合剂膨胀而导致其头部径向破裂机理的研究.现已查明:方镁石(MgO)缓慢的水合作用是导致水泥胶合剂膨胀破坏的主要原因.而有关硫酸盐的膨胀是次要的原因.通过对大量水泥胶合剂的长期浸水膨胀试验,以及对用工厂生产的水泥和实验室配制的水泥胶装的绝缘子的压蒸试验,确定了引起绝缘子破坏所需的膨胀量.根据这个研究,对悬式绝缘子用水泥胶合剂建议根据美国材料标准(ASTM) C151进行的压蒸试验的最大压蒸膨胀限为0.12%左右. 相似文献
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使用质量取代法研究粉煤灰和纳米SiO2单掺及复掺对再生混凝土(RAC)工作性能、抗压强度(7,28,90 d)、抗折强度(28 d)和劈裂抗拉强度(28 d)的影响。浇筑试样时,基于现有的搅拌方式,提出了新的两阶段搅拌法,先将再生粗骨料和纳米SiO2、附加水进行搅拌,使得部分纳米SiO2颗粒能够被再生粗骨料吸收,用于填补老砂浆孔隙和微裂缝。结果表明:随着纳米SiO2掺量增加,再生混凝土的坍落度逐渐减小,复掺粉煤灰能够减少纳米SiO2引起的坍落度损失; 粉煤灰掺量不变的情况下,再生混凝土抗压、抗折和劈裂抗拉强度随着纳米SiO2掺量的增加而增加; 复掺纳米SiO2和粉煤灰不但能够补偿再生混凝土由粉煤灰引起的早期强度降低,而且90 d龄期抗压强度明显高于2种材料单掺的再生混凝土; 纳米SiO2掺量(质量分数)为1%时,再生混凝土在90 d龄期的抗压强度相对再生混凝土提高了3.0 MPa; 复掺纳米SiO2和粉煤灰对再生混凝土的抗折强度、劈裂抗拉强度也有显著提升,S2F30的抗折强度相对于F30增加了24.17%,且劈裂抗拉强度高于2种材料单掺的再生混凝土,相对于F30提高了12.68%。 相似文献
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为了提高活性粉末混凝土(RPC)的力学性能并改善其高温爆裂性,在RPC中将0.3%、0.4%聚丙烯纤维(PP)和0、1%、2%、3%钢纤维(S)组合复掺,共设计8组试件,养护并模拟火灾试验,统计试件在高温(200、400、600℃)作用下的爆裂情况,研究复掺纤维对高温后RPC的抗折和抗压强度、强度损失率、折压比的影响,抗压强度、受火温度与超声波速的规律,确定两种纤维的最佳配合比。结果表明:掺入PP可以改善RPC高温爆裂;RPC抗折、抗压强度、折压比及超声波速随受火温度升高均呈先上升再下降的趋势,复掺入S可提升RPC的抗压、抗折强度和折压比;当S与PP掺量分别为1%与0.3%、2%、0.4%时,RPC未爆裂且强度较高,超声波速与抗压强度的相关性也较高。 相似文献
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《Construction and Building Materials》2010,24(3):241-251
Sixteen alkali-activated (AA) mortars were mixed and cured at water or air-dried conditions to explore the effectiveness and limitation for the application of barium hydroxide (Ba(OH)2) as an additional activator in calcium hydroxide (Ca(OH)2)-activated ground granulated blast-furnace slag (GGBS) system. In order to determine the optimum amount of Ba(OH)2 that is to be added, test specimens were classified into two series. For series I, the Ca(OH)2-to-GGBS ratio by weight was 0% and 7.5%, and the Ba(OH)2-to-GGBS ratio by weight varied from 0% to 10% at a spacing of 2.5% for each Ca(OH)2-to-GGBS ratio. For series II, the Ca(OH)2-to-GGBS ratio was 7.5% and 10%, and the Ba(OH)2-to-GGBS ratio varied up to 3.5%. The flow loss of fresh mortars and the compressive strength development of hardened mortars were measured. In addition, X-ray diffraction (XRD) and energy-dispersive X-ray (EDX) analyses combined with a scanning electron microscope (SEM) image were carried out to ascertain the effect of alkali activators used and the curing condition on the hydration products and the microstructural characteristics of the AA mortars. Test results clearly showed that the water curing condition was more effective than the air-dried curing condition for the formation of the denser calcium silicate hydrate (C–S–H) gels that had a higher molar Si/Ca ratio, resulting in a higher strength development. The addition of 1% Ba(OH)2 also contributed to the stabilization of C–S–H gels at long-term age, which resulted in a further increase in strength with the increase of age. At the same time, the introduction of Ba(OH)2 led to the formation of 2CaO·Al2O3·SiO2·8H2O (C2ASH8) hydrates with higher molar Si/Al and Ca/Al ratios. This would also result in a higher strength development of AA mortars tested. 相似文献
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《Soils and Foundations》2023,63(4):101333
Cement and lime are widely used to stabilize/solidify (S/S) contaminated soils, however, the production of ordinary Portland cement (OPC) and lime causes CO2 emission and consumption of energy and non-renewable resource. In this context, this study proposes a sustainable S/S approach by utilizing an industrial by-product, ladle slag (LS), and carbon dioxide (CO2), to substitute cement and lime for treating cadmium (Cd)-contaminated soil. In laboratory investigation, contaminated soils spiked by Cd with concentrations of 0–32,000 mg/kg were treated by LS with a binder content of 10 % and subjected to conventional curing and carbonation curing for different periods varying from 3 hours to 112 days. The results showed that LS with conventional curing could reduce the leaching of Cd, however, it was still less effective than OPC in S/S of Cd-contaminated soils under the same curing period of 28 days. When CO2 was introduced, LS with CO2 rapidly decreased the leaching of Cd in soils by five orders of magnitude, using only 104 hours to achieve better S/S efficacy than OPC with conventional curing for 28 days. The LS with carbonation curing also sequestered CO2 up to 16 % of LS mass and yielded higher strength than that without CO2. 相似文献
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设定不同配比的再生沥青混合料(RAP)和不同水泥掺量,通过标准击实、无侧限抗压强度、水稳定性、模量性能以及SEM测试,研究了水泥在RAP中的胶结效应。结果表明:RAP中沥青含量与稳定土的质量比(A/S)为0.4时,随着水泥掺量的增大,RAP的最大干密度从1.91 g/cm3增加到2.00 g/cm3。水泥掺量一定时,随着废旧沥青含量的增加,RAP的最大干密度随随之增大;掺6%水泥的RAP无侧限抗压强度从1.48 MPa增加到2.63 MPa,随之减小到2.28 MPa。使用的材料体系中,A/S=0.4,掺6%水泥,用水量9.5%时,再生料获得最好性能。试件浸水后抗压强度普遍降低,但与干燥试件无侧限抗压强度变化趋势一致。对RAP的模量试验表明高温状态下RAP混合料的路用性能最差。SEM测试表明:水泥的水化使得混合料中有针状钙矾石和纤维状C-S-H凝胶相互交织搭接,形成网络结构,将集料颗粒包裹起来,这是RAP产生强度的主要因素。 相似文献
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以钢渣和水泥为主要原料,加入少量石膏(CaSO4·2H2O)与硅灰,制备钢渣水泥基胶凝材料。探讨了CaSO4·2H2O与硅灰掺量对钢渣水泥基胶凝材料强度的影响,并通过XRD、SEM表征,研究钢渣水泥基胶凝材料的水化性能。结果表明:复掺1% CaSO4·2H2O和4% 硅灰的钢渣水泥基胶凝材料3 d抗压强度较未掺CaSO4·2H2O与硅灰提高了59.0%,28 d抗压强度提高了32.4%;CaSO4·2H2O与硅灰的加入不会影响钢渣水泥基胶凝材料水化产物种类;相同龄期内,加入CaSO4·2H2O与硅灰的钢渣水泥基胶凝材料中水化硅酸钙(C-S-H)凝胶和钙矾石(AFt)含量增多,Ca(OH)2晶体含量、晶体尺寸有所减小。 相似文献
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针对传统拉力型和压力型锚杆存在受力集中、锚固体与岩土体界面黏结强度发挥不充分、抗拔承载力偏低的问题,研发了一种新型拉压复合型锚杆。通过对传统锚杆及拉压复合型锚杆开展模型试验,对比研究了不同锚杆的极限抗拔承载力及其锚固性能。结果表明:拉压复合型锚杆极限抗拔承载力比传统拉力型锚杆大幅提高,拉压长度比为1∶2和2∶1时,分别提高79%和161%,且具有更好的位移延性和抗变形能力;拉压复合型锚杆峰后残余抗拔承载力显著提高,传统拉力型和压力型锚杆稳定残峰比最大值均不超过0.40,锚头相对拔出变形ξs=2.5%时,残峰比平均值分别为0.292和0.259;TC360-12锚杆和TC360-21锚杆稳定残峰比最小值分别不低于0.45和0.60,ξs=2.5%时,残峰比平均值分别为0.545和0.790;拉压长度比为2∶1的拉压复合型锚杆即将破坏时,受拉锚固段和承压锚固段协同承载能力更强,界面黏结强度得到充分发挥,锚杆极限抗拔承载力更高。 相似文献